Resting Heart Rate Question

I have been monitoring my resting Heart Rate almost every morning for a few months now and the results seem a bit unusual. There has been a general downward trend (down to 42 on a low day), but the results vary dramatically between 42 and 53. I know that a higher than average resting heart rate can be a sign of over training, but there does not seen to be a correlation between heard riding days and increased Heart Rates.

Biological variability and observer bias will account for this. Be not concerned. BP bounces around even more than pulse rate. By observer bias I mean that the act of checking something where there is a heightened state of concern can affect the results. We get this a lot in the ED where people come in with BP of 240/160 and on recheck with nothing done, the BP is 180/120. Thirty minutes later it is 150/90.
Check a toddlers pulse and it will be 150, let them settle down and start playing and it will drop to 110. Your pulse rate is probably in the 30's when you are deep in sleep at 3am. Steve

I was doing the same last year. I noticed mine would be elevated several BPM the day after a hard ride. From what I've read, this isn't necessarily a sign of 'overtraining' (putting yourself into a deep fitness hole by going too hard for too long) but just a sign that you'd put a training load onto your body that it needed to recover from. At least, I _know_ I wasn't overtrained.

There's a lot of things that can make your HR jump around - so I wasn't concerned about the variance I saw (similar to the ~10BPM you're seeing). But then I'm only 35 now, so I'm not real concerned about my heart at this point.

Heart Rate upon waking can have some significant variability. If you have a full bladder, or were awakened suddenly by an alarm clock, you may have an elevated heart rate. Your heart rate also varies considerably while you are alseep corresponding to the various sleep levels. If you have a access to a high end Polar heart rate monitor that records heart rate data for download to a computer (S710, S720, S725), wear it overnight. You'll be amazed at how active you are while asleep.

BTW, a 42 bpm resting heart rate is very good and something to be quite proud of.